Perhaps this, alone, tells you something about the U.S. Taco's key target: Millennials — with dough. Like the ones who eat several times a week at Chipotle or Panera Bread.

You won't find 99-cent tacos at U.S. Taco Co. The restaurant will sell tacos for as much as $7. Ten different, soft-shell, open-faced tacos initially will be the only menu entrees. One's made with Maine lobster. Another's layered with brisket from Texas. And yet another veggie version is drizzled with Wisconsin cheese.

"We realized that at Taco Bell we weren't reaching all of those who want Mexican food," says Jeff Jenkins, senior brand manager. So, Taco Bell CEO Greg Creed put the project in motion last year. It was kept secret from most Taco Bell employees, says Jenkins. "It was tucked away in a part of the building where not a lot of people venture."

This is not your grandfather's Taco Bell. If you walk out of Taco Bell spending $5 to $7, you'll likely double that at U.S. Taco Co. to the tune of $10 to $15.

"Everyone in the U.S. has become a foodie," says Jenkins. "The first thing young people do in a restaurant is take out their camera and take a picture of their food — and post it on Instagram." Consider: Nearly half of the images posted on Instagram are of food.

This is Taco Bell's long-awaited move to tap into the restaurant world's fastest-growing segment: fast-casual. This is the land inhabited by success stories like Chipotle and Panera Bread — who have figured a way to directly appeal to Millennials. In fact, continued growth in the fast-casual sector — particularly via fast-food chains expanding into the sector — is the No. 1 restaurant trend that the research firm Technomic projects for 2014.

Taco Bell executives already are planning a second U.S. Taco Co. location in Southern California — but they won't say where. The second store, and those after it, will sell milkshakes spiked with beer. (It couldn't get an alcoholic beverage permit for the Huntington Beach location.)

For extra Millennial appeal, the place will pulsate with rock music. It will have an outdoor dining patio. And the kitchen will be set behind glass, so customers can watch the "food theater," says Jenkins.

Most important: Don't look for the Taco Bell name anywhere in the restaurant. "This is an entirely separate brand," says Jenkins. "You will not see Taco Bell."